Oesophageal mucosa has well established protective mechanisms, which operate within pre-epithelial, epithelial and post-epithelial compartments. Since refluxed acid and pepsin always act from the luminal side of the mucosa, protective factors like EGF, operating as a part of pre-epithelial defence, are thought to be pivotal in the maintenance of the integrity of the oesophageal mucosa. The significant contribution of salivary EGF to the quality of the oesophageal mucosal barrier has been demonstrated in an experimental setting and in a clinical scenario. Patients with low salivary EGF levels are predisposed to severe oesophageal damage if they develop gastro-oesophageal reflux and are a high-risk group for development of Barrett's oesophagus. Not only the salivary glands but also the human oesophagus has a profound ability to elaborate and release EGF. Some changes in luminal release of EGF during oesophageal mucosal exposure to intraluminal damaging factors imply its role in the oesophageal protective mechanisms. To exert biological effects within the oesophageal mucosal compartment, EGF requires binding to the ligand-binding domain of its receptor. This process results in receptor dimerisation, autophosphorylation and activation of intracellular signal transduction pathways. EGF receptors are localised on the basolateral and luminal aspect of the mucosal cells playing an important role in fast regeneration of oesophageal epithelium through the high mitotic activity of its proliferative zone. An increase in the rate of salivary EGF secretion during masticatory stimulation suggests its potential therapeutic benefit in the treatment of patients with damaged oesophageal mucosa.

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BackgroundHuman saliva, a complex secretion that contains a mixture of inorganic and organic molecules, plays an essential role in the maintenance of oral health. Mucins are the major macromolecular component of the secretion and are considered the first line of defense for epithelial tissues. The aim of this study was to compare levels of mucins (MUC5B, MUC7, and MUC1) in saliva of young subjects with dental caries.Material/MethodsAll patients had DMF (decay/missing/filled) higher than value 0. Eight subjects with DMF=3 (control group) and 27 adolescents with DMF >11 (research group) were recruited for this study. Clinical evaluation procedures were oral examination, including tooth, periodontal, oral mucosal status, and collection of saliva samples. Saliva was collected for mucin assay. Enzyme-linked immunosorbent assay was used to quantitate MUC5B, MUC7, and MUC1.ResultsOur results indicate that adolescents with very high intensity of dental caries disease had increased levels of MUC1 and MUC5B. The membrane mucin MUC1 protein levels in the group with DMF>11 (research group) were higher compared to the group with DMF=3 (control group), and the increase was statistically significant (p=0.011). Similarly, secreted mucin MUC5B protein levels were higher (p=0.06) in the group with DMF>11 (research group). Although MUC7 protein levels were slightly reduced in symptomatic subjects, the decrease was statistically insignificant (p=0.918).ConclusionsOur data suggest links between the production of mucins, especially MUC1 and MUC5B in saliva, and dental caries disease.

The aim of the study was a determination of the levels of nitric oxide (NO) and its biological markers such as malonyldialdehyde (MDA) and nitrotyrosine in the serum of patients with squamous cell carcinoma (SCC) of the oral cavity and identification of the relationships between NO and those markers. These studies were performed on patients with SCC of the oral cavity before and after treatment. Griess reaction was used for the estimation of the total concentration of NO in serum. The nitrotyrosine level in serum was assessed with an enzyme-linked immunosorbent assay (ELISA) kit, and MDA level using a spectrophotometric assay. Higher concentrations of NO in blood serum were determined in patients with stage IV of the disease before treatment in comparison to the control group and patients with stages II and III of the disease. Moreover, higher concentrations of MDA and nitrotyrosine were determined in the serum of patients in all stages of the disease in comparison to healthy people. After treatment, lower concentrations of NO in the serum of patients with stage IV of the disease were observed in comparison to the amounts obtained prior to treatment. In addition, lower levels of nitrotyrosine in the serum of patients with all stages of the disease were recorded, whereas higher concentrations of MDA were determined in these patients in comparison to results obtained before treatment. The compounds formed with the contribution of NO, such as MDA and nitrotyrosine, may lead to cancer progression in patients with SCC of the oral cavity, and contribute to formation of resistance to therapy in these patients as well. Moreover, the lack of a relationship between concentrations of NO and MDA, and between NO and nitrotyrosine in serum suggests that the process of lipid peroxidation and nitration in patients with SCC does not just depend on NO.

Available data indicating a role for neutrophils in the tumor-host reactions are controversial. In 37 patients with oral cavity squamous cell carcinoma (OSCC), we investigated the expression of a tumor-promoting, proliferation-inducing ligand (APRIL) molecule by peripheral blood neutrophils isolated from blood samples collected at presentation and three weeks after surgery, and the serum levels of TGF-␤ in the same samples. Additionally, we investigated the consequences of TLR4 activation by LPS for the synthesis of APRIL by those cells.The levels of mRNA for APRIL and TLR4 were measured using a real-time PCR method. Western blot analysis was used to assay the expressions of APRIL and ERK1/2 in cell lysates. The results of the present study revealed the unfavorable features of the detection, in the blood, of neutrophils displaying an enhanced expression of the tumor-promoting APRIL molecule. The increased expression and release of APRIL accompanying advanced stages of disease demonstrated by these cells, combined with the increased number of neutrophils, may be an important marker of disease progression in the patient group examined. Simultaneously, an increased level of circulating TGF-␤ in the serum of these patients appeared to be associated with the overexpression of APRIL in their neutrophils. In contrast to the healthy controls, TLR4 expression and the ERK1/2 signaling pathway appear to play only minor roles in APRIL induction in the cells of patients with cancer. The changes presented in the current study suggest that modulation of the expression of tumor-promoting APRIL, in addition to TRAIL and BAFF, might be taken into account in the development of new strategies for supportive immunotherapy of OSCC disease and possibly for other types of neoplasm as well.Key words: oral cavity squamous cell carcinoma (OCSCC), a proliferation-inducing ligand (APRIL), polymorphonuclear neutrophils (PMNs), Toll-like receptor 4 (TLR4), the extracellular signal-regulated kinases 1/2 (ERK1/2), transforming growth factor ␤ (TGF-␤)